Ch-19 Alteration in Hormonal Regulation Flashcards
What are the two diseases of posterior pituitary?
SIADH & Diabetes insipidus
What is another name for ADH?
vasopressin
If there is no ADH, the collecting duct is ____ permeable to water and large volume of urine is produced.
NOT
If there is an excess secretion of ADH from PP = water ____(1) & ___-osmolarity (2)
If there is a reduced secretion of ADH from PP = water _____(3) and ECF _____osmolarity (4)
reabsorption (1); hypo (2); absorption (3); hyper (4)
Which disease of PP occurs when there is a presence of high ADH levels?
SIADH
What are the common causes of SIADH? (3 pts)
(1) ectopic secretion of ADH by tumours
(2) surgery
(3) meds
What type of meds are associated with SIADH?
HYPOglycemic meds, opioids, antidepressants, anti-inflammatory
What tumours are associated with SIADH?
Cancers - stomach, duodenum, pancreas
Lymphomas, sarcomas (bone cancers)
CNS disorders - encephalitis and meningitis
How does surgery affect SIADH?
any surgery increased ADH up to 5-7 days
What is the key feature of SIADH?
increased water reabsorption to peritibular capillaries.
For SIADH, if there is increased ADH secretion, there is _____(1) water channel proteins.
increased
SIADH: If there is an increased water reabsorption in ECF = ___-____ in ECF
hypo-osmolarity.
What is the difference between normal osmolarity/ hyperosmolarity/ hypo-osmolarity?
Normal: match between Na and H2O
HYPER: more Na than H2O
HYPO: less Na than H2O
What are some manifestations for SIADH?
HYPOnatremia – low Na in blood
What are the effects of SIADH in our body?
dependent upon severity and rapidity of onset
How much does the serum Na levels decrease if people has SIADH?
Note: It decreases rapidly!
140-130 mmol/L
How much is the serum Na level of a person with SIADH if they are showing symptoms like VOMITING, ABDOMINAL CRAMPS & WEIGHT GAIN?
130-120 mmol/L
How much is the serum Na level of a person with SIADH if they are showing symptoms like CONFUSION, LETHARGY, MUSCLE TWITCHES & CONVULSIONS?
below 130 mmol/L
T or F: Symptoms of SIADH usually resolve with correction of hyponatremia.
TRUE
Which PP disorder is associated with insufficiency of ADH activity leading to polyuria and polydipsia?
diabetes insipidus
What is polyuria and polydipsia?
polyuria – fq. urine
polydipsia – fq. drinking
What are the 2 forms of diabetes insipidus?
Neurogenic (or central) & Nephrogenic
What are the 2 types of Nephrogenic?
acquired and genetic
What is the cause of Neurogenic?
- low ADH from PP
- lesions on hypothalamus
- PP interference with transport/release of ADH
- brain tumours, aneurysm